16640465 has 8 divisors (see below), whose sum is σ = 20455848. Its totient is φ = 12987520.

The previous prime is 16640453. The next prime is 16640473. The reversal of 16640465 is 56404661.

It can be written as a sum of positive squares in 4 ways, for example, as 132496 + 16507969 = 364^2 + 4063^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16640465 - 2⁶ = 16640401 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40382 + ... + 40791.

It is an arithmetic number, because the mean of its divisors is an integer number (2556981).

Almost surely, 2^16640465 is an apocalyptic number.

It is an amenable number.

16640465 is a deficient number, since it is larger than the sum of its proper divisors (3815383).

16640465 is an equidigital number, since it uses as much as digits as its factorization.

16640465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81219.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 16640465 is about 4079.2726067278. The cubic root of 16640465 is about 255.3025500288.

It can be divided in two parts, 1 and 6640465, that added together give a palindrome (6640466).

The spelling of 16640465 in words is "sixteen million, six hundred forty thousand, four hundred sixty-five".